Jack



April 16, 1929.

F. H. SC/HWERIN JACK Filed March 1928 2 Sheets-Sneak April 16, 1929. 1H. SCHWERIN JACK , 1928 2 Sheets-Sheet Filed March 2 I INVENTOR A 776ANE Patented Apr. 16, 1929.

' UNITED STA TES PATENT OFFICE.

FRANK H. SCHWERIN, or BELLEVUE, P'ENNsY VANIA, ASSIGNOR To THE DUFF-NORTON MANUFACTURING COMPANY, or PITTSBURGH, PENNSYLVANIA, A COR-PORATION OF PENNSYLVANIA.

JACK.

Application filed March 2,1928. Serial No. 258,495.

The invention relates to jacks and more particularly to lifting jacks.

The general object of the, invention is to provide a jack of the gearedtoggle type which is very simple in construction, strong and efficient,and the elements and arrangen'ient of which are such as very greatly tofacilitate the manufacture and cheapen the cost of production. I

In the accompanying drawings forming part hereof:

Fig. 1 is a side elevation of the improved toggle jack in a partlyraised condition, with a portion of the screw shaft broken out, andshowing also a long extension handle connected with the jack by means ofthe preferred form of the separable flexible operating connection,intermediate portions of the handle, constituting most of its length,being broken out;

' Fig. 2 is sectional view of the part on the inner end of the separablehandle, shown in a position in relation to Fig. 1 in which it can 1 beentered into engagement with the jack; Fig. 3 is an end view of the headon the actuating element of the jack illustrated in Fig. 1' I F ig. 4=is a fragmentary view with one part in section and another partinelevation, 11- lustrating another .form of separable operstingconnection between the jack and han- Fig. 5 is a cross-section on theline 55 of Fi 4 Figjfi is a sectional view of the ack proper taken inthe central vertical planeof the axis of the screw, which itself is inelevation, full and broken lines being used to show different positionsof the jack; and

tion through the jack.

' The jack has a suitable base 2 provided with spaced portions 3. Theseportions are pierced with alined openings for two pivots 4 and 5, theends of which are upset outside of the portions 3, and it will be notedthat the openings are so located that the axes of these pivots do notlie in a horizontal plane but are-at somewhat different levels.

Two pairs of lower arm elements 6 and-7,

forming two double arms, are swung on the pivots 4: and 5, the membersof each double am being separated by spacers 10.

Two pairs of upper arm elements 8 and 9,

Fig. 7 is a central vertical transverse secalso forming two double arms,are pivoted to the arms 6 and 7 on trunnions 11 and 12 proposed betweenthe upper'ends of the pairs of arm elements 8 and 9.

The actuating means of the tick preferably comprises a screw shaft 21,which is preferably a right and left hand screw, engaging the members 13and 14 formed as nuts.

The arms 6 arid 8 form a toggle, and the arms 7 and 9 form anothertoggle, the two toggles flexing in opposite directions. It

will be understood that corresponding elements of the double arms 6 and7 lie in the same vertical planes, and similarly the elements of thedouble arms 8 and 9.

The lower ends of the arm elements 6 and I 7 are formed with integraltoothed gear or segment formations 22, inter-gearing the toggles at thebottom. The upper ends of the armelements 8 and 9 have the sameformations 22 inter-gearing the toggles at the top.

An important feature of the jack thus far described is that all thearms, and indeed all.

eight of the arm elements 6, 7, 8 and 9 are duplicate andinterchangeable, being of the same length, having the same pivotopenings, and in particular having the same number of teeth 22 on oneend of each, in precisely the same position on each link. This involvessetting the pivots 4 and 5, or the centers of these pivots, at differentlevels on the base, as has been mentioned previously, in order that theteeth may intermesh. The centers 11 and '12 lie at similarly differentrelative levels, and the centers 15 and 16 connect the arms '8 and 9with the upper member 17 also at the same relative difier'ence of level.This last does not necessitate setting the top at an inclination,since,by appro priate relation between'the top rest 18 and the pivot openingsin the-side portions 19, the top rest can be leveled.

Heretofore, in geared toggle or lazy tong jacks, it has been necessaryto make different arm elements in order that the teeth might mesh, andthese elements have not been interchangeable. Thepresent jack is moreeasily produced, at considerably less cost indies, and with much greaterfacility in assembling, since any element will go in any position. Also,in caseof repair, an arm element from a single stock will replace anyarm element of the jack. I

The inclination of the actuatingshaft 21 resultingfrom the difference inlevel. of the middle pivots has a further advantage in reducing theangle between this shaftand an I operating handle in the operation ofthe jack.

' Coming now to the operating handle, it

- will be seen that one end of therotary actuatfrom the narrow or shankportion of the part 23 when the axes of the parts are approximately at90, or thereabouts, that is to say, at a decided angle, but when thehandle is straightened more or less in line with the rotary actuatingelement of the jack, the pins 27 in engagement with the grooves 24retain:

the handle against'coming off sideways and against being pulled offendwise. Rotation of the handle will thus raise and lower the jack, andthe handle can also be used to push the Jack into place and to draw itout after the operation is over. The longitudinal convexity of the facesof the head 23 enables the ,f handle to be held at a range ofinclinations and still to operate the member 21.

The handle may be composed of two ections 30 and 31 that can be takenapart, the sections being connected by a sleeve 28 fixed to one sectionand having slots to be engaged.

by pins 29 on the other section. The section parts 23 and 26, or 23- and26*, might be reversed with respect to the jack and handle.

I claim:

1. A toggle jaclg comprisinga base, a top, eight arm elements formingtwo toggles between the base and' the top, and means for actuating'thetoggles, oneend of each arm element having an integral toothed gear format-ion, and all eight arm elements being duplicate and interchangeable.

2. A toggle jack comprising a base, an upper member, two toggles, pivotsconnecting the arms of the respective toggles with each other, otherpivots connectingthe lower toggle arms with the base and the uppertoggle arms with the upper member, said arms having integral meshinggear tooth formations, at the top and ,bottom, and means,for'a'ctuating'the toggles, all corresponding pivots of the two togglesbeing. at different levels, and all of the arms being duplicate andinterchangeable.

3. A toggle jack com rising a base, an up per member, two togg es,pivots connecting the arms of the respective toggles with each other,other pivots connecting the lower toggle arms with the base and theupper toggle arms with the upper member, said toggles having integralmoshing gear tooth formations at the top and bottom, allcorrespondingivots of the two toggles being at different levels, and allof the arms being duplicate and interchangeable, and an inclined screwshaft connecting the-middle pivots.

FRANK H. SCHWERIN.

